BioTENS (1 channel) and QuadraTENS (2 channels) are low frequency TENS devices. Simutaneous bilateral stimuation of the 5th and 7th cranial nerves is used for pain relief and to relax all of the masticatory muscles. A balance control, specifically designed for the dental application, allows for equalizing the patient's response bilaterally. QuadraTENS also includes the BURST mode for trapezius.